<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    body {
      font-family: Arial, sans-serif;
      background-color: #f0f0f0;
      color: #333;
      padding: 20px;
    }
    div {
      background-color: #fff;
      border-radius: 5px;
      box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
      padding: 20px;
      margin: 20px auto; 
      width: 300px;
    }
    h1 {
      font-size: 24px;
      margin-bottom: 10px;
    }
    p {
      font-size: 16px;
      margin-bottom: 20px;
    }
    button {
      background-color: #007bff;
      color: white;
      border: none;
      padding: 10px 15px;
      border-radius: 5px;
      cursor: pointer;
    }
    button:hover {
      background-color: #0056b3;
    }
    
  </style>
</head>
<body>
  <div>
    <h1>Hello World</h1>
    <p>这是popup界面</p>
    <button id="btn">点击按钮</button>
  </div>
</body>
<script src="popup.js"></script>
</html>